According to the Schulze-Hardy rule in the convention that the flocculation value of a counter-ion varies as $1/ z^{6}$ (z = charge of the coagulating ion), the flocculation value of $NaCl$ for a negative sol is 58.4 mmol/L. Predict the flocculation value of $AlCl X_{3}$ for this sol in micromoles per litre (two decimals).

Numerical answer type, answer in umol/L, tolerance 0.05.

Answer: 80.11 umol/L

The ratio of flocculation values is

(z_{A l} / z_{N a})^{6} = 3^{6} = 729

. Predicted value

= 58.4/729 = 0.08011 mmol/L

, i.e.

80.11 μ mol/L